1. Field of the Invention
The present invention generally relates to a flexible printed circuit board for electronic equipment. In particular, the present invention relates to a flexible printed circuit board for electronic equipment, in which a folding part is folded by a force generated when a connector included in the flexible printed circuit board is engaged.
2. Description of the Related Art
In general, the term “portable communication apparatus” means an electronic apparatus which a user can carry with him/her to perform wireless communication with another party. As examples of the portable communication apparatus, there are hand held phones (HHP), Codeless Telephone (CT)-2 cellular phones, digital phones, personal communication service (PCS) phones, and personal digital assistants (PDAs). Conventional portable communication apparatuses may comprise various types according to their appearance. For example, wireless terminals comprise bar-type wireless terminals, flip-type wireless terminals, and folder-type wireless terminals according to their appearance. The bar-type wireless terminal has a single housing shaped like a bar. The flip-type wireless terminal has a flip or a cover which is pivotally mounted to a bar-shaped housing by a hinge part. The folder-type wireless terminal has a folder coupled to a single bar-shaped housing by a hinge part in such a manner that the folder can be rotated in order to be folded to or unfolded from the housing.
Further, wireless terminals may comprise rotation-type wireless terminals and sliding-type wireless terminals depending on the particular manner the wireless terminal is opened. In the rotation-type wireless terminal, two housings are coupled to each other to allow one housing to rotate open or closed with respect to the other while facing each other. In the sliding-type wireless terminal, two housings are coupled to each other to allow one housing to slide open or closed with respect to the other. These variously classified portable wireless terminals can be easily understood by those skilled in the art. The conventional portable terminals comprise antenna devices, data input/output devices, and data transmission/reception devices. As the data input/output devices, keypads allowing data input through a finger press task are generally used, or touch pads or touch screens may be used.
Liquid crystal displays (LCD) are generally used to display data output from data output devices. For video telephony, conventional portable communication apparatuses are equipped with camera lenses as photographing means which enable users to perform video telephony with others or photograph desired objects.
A sliding-type wireless terminal 10 among various types of wireless terminals will be described with reference to FIG. 1.
In the sliding-type wireless terminal 10, a sliding housing 30 slides a predetermined length along the length of the sliding-type wireless terminal 10 on a main body housing 20 and is opened. The sliding-type wireless terminal 10 has an advantage of adapting to users' various tastes over conventional folder-type terminals.
As illustrated in FIG. 1, the sliding-type wireless terminal 10 comprises the main body housing 20, the sliding housing 30 that slides downward or upward ½ of the length of the main body housing 20 on the main body housing 20, a sliding keypad 31, an LCD 32 for a display function, and a speaker device 33 on the front surface of the sliding housing 30, and a 3×4 main body keypad 21 and a microphone device 22 on the front surface of the main body housing 20.
As illustrated in FIGS. 2 through 6, in the sliding-type wireless terminal 10, a printed circuit board (PCB) 24 is accommodated in the main body housing 20, and a LCD PCB 34 is mounted in the sliding housing 30.
With respect to FIG. 9, a flexible printed circuit board (FPCB) 40 is depicted wherein a micro circuit is printed on a thin board made of flexible plastic as described in more detail below. The FPCB 40 and a circuit board connector 50 printed on each of the PCBs 24 and 34 are used as electric connection means for connecting the PCB 24 and the LCD PCB 34.
The FPCB 40 is a cable that connects the PCB 24 and the LCD PCB 34 to enable components to exchange power sources and signals. The FPCB 40 is usually used when one of two components may be moved or the two components cannot be directly connected.
As illustrated in FIG. 5, the circuit connector 41 connected to the circuit board connector 50 included in the PCB 24 and the LCD PCB 34 is provided at both ends of the FPCB 40. The circuit connector 41 is connected to the circuit board connector 50, which enables signal transmission.
As illustrated in FIGS. 2 and 5, a plurality of points (not shown) for electric connection are provided in the circuit board connector 50 and is engaged with corresponding contact points 40e in FIG. 5 on a portion of the FPCB 40 that extends from the circuit connector 41 of the FPCB 40. At this time, an opening 51 into which the circuit connector 41 can be inserted is formed in the circuit board connector 50 and the opening 51 has a cover 52 for preventing foreign substances from being introduced.
As illustrated in FIG. 4, a cross-section of the circuit connector 41 of the FPCB 40 shows a base film 40a, a circuit pattern 40b on the base film 40a, and a protection film 40d adhered onto the circuit pattern 40b by an adhesive 40c which constitute the flexible plastic board on the FPCB 40, and a compression part 60 either side thereof.
A compression part 60 whose surface is processed with electrolytic copper is adhered to the circuit connect 41 using an interlayer adhesive 61. A plating interface 70 of the compression part 60 (hereafter, referring to a second plating interface) for bending the circuit connector 41 is provided on the FPCB 40 at one end of the compression part 60.
The compression part 60 adheres a metal plate 63 made of electrolytic copper under the base film 41a and on the protection film 41d by an interlayer adhesive 61.
However, in an FPCB 60 of a conventional portable terminal, a plating interface inside (hereafter, referring to a first plating interface) a compression part of a circuit connector 41 and a second plating interface 70 of the compression part 60 is respectively provided in the form of a straight as illustrated in FIGS. 3 through 9. As a result, when a circuit connector 41 of the FPCB 40 is assembled with a circuit board connector 50, a force can be applied to the weak first plating interface, instead of the compression part 60. At this time, the first plating interface may be damaged when being folded, causing degradation in a process of assembling the FPCB.
To solve the problem, shield tape or shield foam is additionally adhered to the interface between the compression part 60 and the first plating interface, thereby preventing damage. However, the additional process of adhering the shield tape or shield foam increases time, and the additional use of the shield tape or shield foam increases manufacturing cost.
Moreover, stress concentration occurs at the compression part 60 of the circuit connector 41 and the first plating interface due to sliding after the circuit board connector 50 and the circuit connector 41 of the FPCB 40 are engaged. As a result, repetitive sliding causes intensive rotation or folding and thus cracks at the compression part 60 of the circuit connector 41 and the first plating interface form.